Clad metal pack and method of making the same



July 22, 1958 D. 1 FREYBERGER 2,843,922

CLAD METAL PACK AND METHOD OF MAKING THE SAME Filed Oct. 14, 1955 3 Sheets-Sheet 3 F/f. J.

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United States Patent O CLAD METAL PACK AND METHOD OF MAKING THE SAME Donald L. Freyberger, Coatesville, Pa., assignor to Lukens Steel Company, Coatesville, Pa., a corporation of Pennsylvania Application October 14, 1955, Serial No. 540,452

1 Claim. (Cl. 29-187.5)

This invention relates to a clad metal pack and the method of making it, and more particularly to a pack which has an expansion connector between the clad metal plate and the backing metal plate.

The principal object of the invention is to provide a method and means of uniting dissimilar metals so that one may expand with respect to the other without rupturing the expansion connector between them.

A further object of the invention is to provide an expansion connector between two dissimilar metallic plates having different co-ecients of linear thermal expansion.

A still further object of the invention is to provide an expansion connector in which a metal member, such as a steel bar, which may take various forms, is used to span the joint between two contacting metals having different thermal coefficients of expansion, the bars being secured to both contacting metals by welding.

These and other objects of the invention will appear hereinafter in the following specification which, taken with the accompanying drawings, constitutes a complete disclosure of the invention.

It has 'been found that the greatest problem in the production of clad plates by the two-ply method rests in the difference in linear thermal expansion between the `clad metal and the backing metal. The expansion connector of this application is designed to eliminate this problem. The saine basic principle is employed in all of the forms of expansion connector disclosed in this application. In all of the forms used, a metallic bar is used to span the joint between the clad metal plate and the metal `backing plate. The thickness of the bar used to span the joint will depend on the gauge of the clad metal plate and the linear dimensions and should be as small as possible. The critical thickness of the bar may be controlled by gouging it out on one side or in some similar way. The bar should be as wide as possible in order to reduce the shearing stress imposed on the welds during the rolling operation of the clad pack. This width would depend on the thickness of the backing plate.

In the drawings:

Figure l is a view in section through the expansion connector of one form of the invention;

Figure 2 is a view similar to Figure l, showing another form of the invention in which one side of the spanning bar is recessed;

Figure 3 is a sectional view similar to Figure 1 but showing a different form of weld connection between an edge of the connecting bar and the cladding plate;

Figure 4 is a view in section through still another form of expansion connector in which the connecting bar has a curved portion at one edge;

Figure 5 is a view in section similar to Figure 4, but showing a bar substantially semi-circular in cross section spanning the joint between the cladding plate and the backing plate;

Figure 6 is a plan view of the types of expansion con- 2 nectors used in Figures 1, 2 and 3, showing a corner reinforcing steel bar; and

Figure 7 is a detail perspective view of one corner of the pack of Figure 6, showing the corner reinforcement.

Referring to the drawings, 2 represents the steel backing plate'used in the pack and 4 is a cladding plate or insert of any suitable metal which is to Ibe bonded to the backing plate. l In the form of Figure 1, the expansion connector is formed by providing a rectangular bar 6 which overlaps the joint between the plate 2 'and the plate.` 4. This bar is secured to the plate 2 and the plate 4 by the welds 8 and 10.

In the form of Figure 2, the bar 12 is provided with a bevel 14 at one edge and a gouged-out portion 16 between its ends. Since the edge of the bar adjacent the cladding plate is beveled inwardly, the weld 18 at this edge is generally V-shaped in cross section.

The connector shown in Figure 3 is substantially the same as that shown in Figure l except that the outer edge of the bar adjacent to the insert is bevelled as in Figure 2 and the weld 20 is triangular in cross section.

In Figure 4, the clad plate is spaced from the edges of the backing plate and a bar 22 of substantially an L-shape in cross section connects the clad plate and the backing plate. As clearly shown in this figure, the shorter leg 24 of the bar 22 engages over the sides of the backing plate 2 and has its edge abutting an edge of the cladding plate. The longer leg 26 of the bar engages the backing plate and is secured thereto by the weld 8 as in Figures l, 2 and 3. As clearly shown in this figure, the leg 26 of the bar is bent outwardly adjan cent the shorter leg to provide a space 28 between the bar and the backing plate. The shorter leg 24 of the bar 22 is secured to the cladding plate by a weld 30 similar to that shown in Figure 2.

Referring now to the form of Figure 5, the Ibar which forms the expansion connector is shown at 32 and is of substantially semi-circular form in cross section and bevelled at its edges 34 to form spaces for the welds 36 Iwhich connect the bar to the backing plate and the cladding plate.

Figures 6 and 7 show still another form of the expansion connector used in the pack of this application. This connector comprises a Ibar 6 arranged on each of the sidesjtof the pack and secured thereto and to the cladding plate by welds 38 and reinforced at each corner by a reinforcement in the form of an angle lbar 40 which overlaps and is welded to the bars 6 at 42.

The welds between the expansion connector or bar and the cladding and backing members should be as heavy as possible with the size of connector used. The weld between the connector or bar and the insert or cladding plate should be made with a suitable electrode, while the IWeld between the bar and the steel backing plate will be made with a steel electrode of any suitable type material.

The term bar or bar means applied to the members 6, 12, 22 and 32 in the drawings is intended to cover any metallic member that may 'be used to span the joint between the backing plate 2 and the cladding plate 4, regardless of its cross sectional shape. While the bar 6 has been described as being rectangular in shape, it will be understood that any other suitable shape could be used.

The pack can be rolled with the clad material either up or down, and while the rolling mill speed and the amount of the rolling mill reductions need not be restricted, experience has indicated that a slow mill speed and light reductions are to be preferred.

The above description and drawings disclose five embodiments of the invention, and specific language has v 3 been employed in describing the figures. It will, nevertheless, be understood that 'no limitations of the scope of the invention are hereby contemplated, and that various alterations and modifications may be rnade as would occur to one skilled in the `art to whichthe invention relates.

I claim:

A clad metal pack having substantially parallel upper and lower side faces comprising a lower steel backing plate and an upper metallic cladding plate on the upper face of said backing plate, the edges of said cladding plate being spaced inwardly from the edges of vsaid backing plate and aranged in parallel relation thereto, said Vcladding plate having a different coelicient of linear eX- pansion than said backing plate, a metallic bar spanning the joint between the edges of said plates, said bar being substantially L-shaped in cross section and having its longer leg engaging the outer edge face of said backing plate and the shorter leg having its inner side face engaging the top face of said backing plate, the edge of said shorter leg engaging the adjacent edge of said cladding plate, the outer face of said shorter leg being spaced below `the upper face of said cladding plate, a weld at the juncture of said last-mentioned faces, said weld being located below the top face of said cladding plate, a weld connecting the lower edge of said longer leg to the adjacent edge of said backing plate, and that portion of said bar adjacent the junction of said legs being spaced from said backing plate to make the bar more readily deformable and to allow for relative expansion between said plates without rupturing the welds las the pack is 'being rolled.

References Cited in the le of this patent UNITED STATES PATENTS Acre May l, Johnson Oct. 29, Goulding July 8, Keene Apr. 26, y Brown July 19, 

